Aeroplane propeller



June 2, V1925.

l. c. DEGN AEROPLANE PROPELLER Filed May 20, 1924 Patented June 2, 1925.

PATENT O FICE.

IRWIN CHARLES DEGEN, or cHAsKA, MINNESOTA.

AEROPLANE PROPELLER.

Application led May 20, 1924. Serial No. 714,557.

To all whom t may concern:

Be it known that I, IRWIN CHARLES DnGnN, a citizen of the United States,residing at Chaska, in the county of Carver and State of Minnesota, haveinvented a new and useful Aeroplane Propeller, of which the following isa specification.

My invention relates to improvements in 'propellers for aircraft.

An object of the invention is to provide a propeller designed andequipped with means for reducing edgewise resistance, whereby thepropeller may function with maximum eiciency.

lVith the foregoing and other objects in view, which will appear in thefollowing description, the invention resides in the novel combinationand arrangement of parts and in the details of construction hereinafterdescribed and claimed.

In the drawings, Fig. 1 is a side elevational view of an embodiment ofmy invention, parts thereof being broken away to disclose structuralarrangement otherwise concealed; Fig. 2 is a front elevational viewillustrating, particularly, the blade and its relation with a powerunit; Fig. 3 is a detail sectional view taken as on the line 3 3 of Fig. 2 and Fig. 4 is a similar view taken as on the line ll--il of Fig.3.

Referring to the drawings, it Will be seen that my improved deviceincludes propeller blades 10 resembling in outward appearance suchblades as are ordinarily used on. aeroplanes and other aircraft. Aspecial hub A is provided in the present instance, the same being hollowand comprising a forward restricted stud 11 and a rear, enlargeddrum-like portion 12 having spaced annular flanges 13, 14 thereon. Theinner surfaces of these flanges 13, 14: are beveled (Fig. 1), the lattersupplying a connecting medium for the attachment of the hub A to aflange 15 of a motor crank shaft 16. Fitted about the portion 12 of thehub A. andfbetween the beveled sides of the flanges 13, 14 is adiametrically divided annulus 17 capable of being taken up when worn,said annulus being formed with an internal annular channel 17 therein.This channel 17 is in constant communication with the in` terior of thehub A through radial openings 12u therein. A suction pump B ofconventional pattern is preferably driven as by means of a belt 18overreaching a pulley 19 on the pump shaft 20 and a pulley 21 on thecrank shaft 16 or other power driven shaft. Pipe connections 22 bringthe pump B into communication with the channel 17 in the annulus 17.Said pipe connections 22 also serve to hold the annulus 17 againstturning, but it is evident that other means may be conveniently employedfor this purpose.

Reaching longitudinally of each blade 10 and through that portionthereof having thickest stock is a pipe or conduit 23.y A plurality oflateral passageways 24 in each blade communicate with the conduit 23therein, said passageways opening at the advanclng'edge of the blade.With the suction pump B in operation and drawing air from the front ofthe advancing edges of the blades 10 through the passageways 24,conduits 23, hub A and pipe connections 22, it w1ll be understood thatthe frictional resistance of the air against said advancing edges willbe minimized due to the rarefication of said air along those lines.Attending this result, the propeller operateswith greater eifciency thanwould otherwise be the case.

C-hanges in the specific form of my invention, as herein disclosed, maybe made within the scope of what is claimed without departing from thespirit of my invention.

Having described my invention, what I claim as new and desire to protectby Letters Patent is:

1. In a. device of the class described, a hollow hub for attachment tothe propeller shaft of a motor, propeller blades mounted radially onsaid hub, each blade having a longitudinal duct therein communicatingwith said hollow hub and also having lateral passageways opening fromthe advancing edge of the blade into said duct, and air exhausting meanscommunicating with said hollow hub.

2. In a device of the class described, radially related blades, eachblade having a longitudinal duct therein and lateral passageways leadingfrom the advancing edge of the blade to said duct, and means forexhausting the air from said ducts and passageways.

3. In a device of the class described, a hollow hub designed forattachment to the propeller shaft of a motor, propeller blades mountedradially on the forward end of the hub, each blade having a conduitextending longitudinally thereof and also passageways opening at theadvancing edge of the blade and leading to said conduit, the conduitcommunicating with said hollow hub, said hub having radial openingsatthe rear end thereof, an annulus encircling said end of said hub andformed with an internal annular channel communicating with said havingradial openings therein and spaced annular flanges at, either side ofsaid openings, said langes being beveled at their inner sides, propellerblades mounted radially on said stud, each blade having a conduitextending longitudinally thereof andaalso passagewa s openin at theadvancing edge of the bla e and lea ing to said conduit the conduitcommunicating with the hollow stud, an annulus divided diametrically forthe taking up of wear and fitted over the drum-like portion of said huband between said anges, said annulus having an internal annular channeltherein communicating with the radial openings in said hub and a suctionpump communicating wit said channel. Y

In testimony whereof, I have signed my name to this specification.

IRWIN CHARLES DEGEN. l

